Higher HA Research Articles

Differential responses of Helicoverpa armigera C-type immunlectin genes to the endoparasitoid Campoletis chlorideae.

The C-type lectins mediate nonself recognition in insects. The previous studies focused on host immunlectin response to bacterial infection; however, the molecular basis of immunlectin reactions to endoparasitoids has not been elucidated. The present study investigated the effect of parasitization by Campoletis chlorideae on hemagglutination activity (HA; defined as the ability of lectin to agglutinate erythrocytes or other cells), and transcriptional expression of C-type immunlectin genes in the larval host, Helicoverpa armigera. Parasitization induced four- to eightfold higher HA in the parasitized larvae, compared to nonparasitized larvae at days 2 and 6 postparasitization (PP), however inhibited HA at other days PP. Eight C-type lectins were differentially expressed in different host developmental stages, from feeding to wandering stage. The mRNA levels of HaCTL1, HaCTL3, HaCTL4, and HaCTL5 were upregulated and HaCTL2 and HaCTL7 were downregulated. Tissue analysis showed that HaCTLs were mainly expressed in fat body or hemocytes, while HaCTL5 was highly expressed in testes. The effects of parasitization on the lectin expression patterns differed. Lectins except HaCTL6 or HaCTL5 were significantly down- or upregulated in parasitized larvae at day 4 or 6 PP compared with that of nonparasitized larvae. We infer from our results that C-type immunlectins are involved in host-parasitoid interactions, and parasitization alter host immunlectin levels both in inhibiting and promoting host immune defenses to endoparasitoids. These immunlectin genes indicated an altered physiological status of the host insect, depending on developmental stage, tissue, and parasitization.

Development of the novel coating formulations for skin vaccination using stainless steel microneedle.

This study focused on the development of novel coating formulations for stainless steel microneedles against influenza A virus. With in vitro studies, various viscosity enhancers and stabilizers were screened based on the hemagglutination activity of the vaccine, which was coated and dried onto a stainless steel chip at room temperature for 1day. Following the long-term storage test, the hemagglutination activity and particle size of the vaccine, which was formulated with conventional or methylcellulose or hydroxyethyl cellulose and dried onto the microneedle, were monitored. Next, to evaluate the in vivo immunogenicity and protection effect of each dried vaccine formulation, mice were immunized by the antigen-coated microneedle, which had either the conventional or the proposed formulation. Two novel formulations were chosen in the preliminary screening, and in further evaluations, they exhibited a 20% higher HA activity during storage for 3months, and no aggregation was observed during storage after drying. In a mouse model, the microneedle with the novel formulation elicited a higher level of IgG and IgG2a was more prevalent in the IgG isotype profile. In addition, mice immunized with the HEC-coated microneedle survived with small weight loss (>90%) against lethal challenge infection. Overall, the novel formulation hydroxyethyl cellulose preserved significantly higher HA activity during the production and storage of the microneedle as well as improved the in vivo immunogenicity of the vaccine.

Effect of nano-hydroxyapatite reinforcement in mechanically alloyed NiTi composites for biomedical implant

Equi-atomic NiTi alloy composites reinforced with 0, 2, 4 and 6vol.% nano-hydroxyapatite (HA) were successfully synthesized using pressureless sintering. Pure Ni and Ti elements were ball milled for 10h in order to produce a mechanically alloyed equi-atomic NiTi alloy (MA-NiTi). Mechanically alloyed NiTi and HA powders were blended, compacted and then sintered for 3h at 1325K. The sintered density varied inversely with volume percent of HA reinforcement. The X-Ray diffraction spectra and SEM images showed the formation of multiple phases like NiTi, NiTi2, Ni3Ti, and Ni4Ti3. The back scattered-SEM image analysis confirmed the presence of Ni-rich and Ti-rich phases with increasing HA content. The 6vol.% HA reinforced composite showed Ni3Ti as the major phase having the highest hardness value which can be attributed to the presence of relatively harder phases along with higher HA content as a reinforcement. The composite of MA-NiTi with 2vol.% HA manifested the most desirable results in the form of better sintering density mainly due to the minute decomposition of NiTi into other phases. Therefore, the 2vol.% reinforced MA-NiTi composite can be exploited as a novel material for manufacturing biomedical implants.

Prediction of Compressive Strength of Biodegradable Mg–Zn/HA Composite via Response Surface Methodology and Its Biodegradation

This work aimed to fabricate magnesium zinc/hydroxyapatite (Mg–Zn/HA) composite via powder metallurgy method and to develop a mathematical model to predict the compressive strength of the composite using response surface methodology method. The effect of various mechanical milling parameters, milling speed (200–300 r/min), ball-to-powder weight ratio (5–12.5) and HA content (2.6–10 wt%) on the compressive strength of Mg–Zn/HA composite was investigated. The model shows that high compressive strength of Mg–Zn/HA composite was achieved when the powders were prepared with high milling speed and ball-to-powder weight ratio and low HA content. The mathematical model was adequate with error percentage lower than 3.4%. The microstructure of Mg–Zn/HA composite with different process parameters revealed that fine microstructure was observed at high milling speed and ball-to-powder weight ratio while agglomeration of HA was found in composite with 10 wt% HA. The agglomeration of HA led to degradation of interfacial bonding strength between matrix and reinforcement phases and hence decreased the overall compressive strength of Mg–Zn/HA composite. Biodegradation test revealed that sample with higher HA content had more weight gain and there was more formation of hydroxyapatite. Mg–Zn/HA composite with 8 wt% HA was found to be the best candidate for implant application because it had considerable compressive strength and good biodegradation properties.

Abstract P227: Cardiovascular Disease (CVD) Risk Factors Have Opposite Associations with Abdominal Aortic Calcium (AAC) Density and Volume: The Multi-Ethnic Study of Atherosclerosis (MESA)

Background: AAC predicts future CVD events independently of CVD risk factors. The standard AAC score, the Agatston method, up-weights for greater calcium density, thus models higher calcium density as associated with increased CVD risk. We evaluated this model by investigating associations of CVD risk factors with AAC density and volume separately. Methods: Multivariable linear regression was used to investigate the independent cross-sectional associations of CVD risk factors, markers of inflammation, and potential promoters of calcification with AAC density and ln (AAC volume). AAC density was calculated as: Density = Agatston / (volume, mm 3 / CT scan slice thickness, mm). Agatston = area, mm 2 X density. Results: In 1413 MESA participants with prevalent AAC, mean age was 65 ± 9 years, mean AAC density was 3.0 ± 0.6, 52% were men, 44% were European-, 24% were Hispanic-, 18% were African-, and 14% were Chinese Americans (EA, HA, AA, and CA respectively). In fully adjusted models, older age was non-significantly associated with lower AAC density, but significantly associated with higher ln (AAC volume) (Figure). Compared to EA, we observed AAC density was significantly higher in CA, non-significantly higher HA and AA, but ln (AAC volume) was significantly lower in CA, HA, and AA. Also, smoking, alcohol use, family history of myocardial infarction, higher systolic blood pressure, elevated total cholesterol, and interluken-6 were significantly associated with higher ln (AAC volume), but not AAC density. Lastly, lower body mass index, higher serum HDL and calcium were significantly associated with higher AAC density, but associations with ln (AAC volume) were in the opposite direction. Conclusion: A greater burden of CVD risk factors was associated with higher AAC volume, but not AAC density. Thus, the Agatston method of up-weighting AAC scores for greater density in CVD risk prediction may be inappropriate. Investigators should evaluate separately associations of AAC density and volume with CVD events.

Determination of in-vivo growth kinetics of virulent Newcastle disease virus in layer chicken

The research work was conducted on 105 layer chicks with a view to determine the rate of distribution of neurotropic virulent Newcastle disease virus (NVNDV) in various organs following infection through natural (intranasal, intraocular and oral) and parenteral (intravenous, intramuscular and subcutaneous) routes of inoculation at different ages (7, 15 and 28 days of old). Each bird received a dose of 0.2 ml contained 300 ELD50 of reference NVNDV. The highest body temperature (?1080F) was recorded in the birds of almost all the experimental groups within 48 to 72 hours of PI. Appearance of clinical signs was observed earlier (48 to 72 hours of PI) in parenterally infected birds than those of inoculated through natural routes. The shortest duration (24-48 hours of PI) and longest duration (74-138 hours of PI) of death time were recorded in birds those inoculated through IV and oral routes of infection respectively. Isolation of NDV was positive from day 2 of PI and onward in all the groups with some minor variations in some cases. The CEF system was found more sensitive for the isolation of viruses compare to that of avian embryo. The highest HA titre of NDV was found in the brain tissue followed by lungs and kidney. Significantly (p<0.01) higher HA titre of NDV isolate was recorded in the birds of all the experimental groups inoculated through IV route. Following infection, the MDA titre decreased day by day in the birds with the increase of HA titres of NDV.Asian J. Med. Biol. Res. December 2015, 1(3): 526-536

Synergistic Removal of Humic Acid in Water by Coupling Adsorption and Photocatalytic Degradation Using TiO2/Coconut Shell Powder Composite

The feasibility of applying nanoscale TiO2/coconut shell powder (TCNSP) composite to remove HA in aqueous solution was evaluated, and the optimization of the photocatalytic systems using newly developed TCNSP composite was performed. The developed TCNSP composite has high specific surface area (i.e., 454 m2/g) and great porosity (i.e., 66.9%) with pore size of less than 5 μm. High removal efficiencies (≥95%) of HA were observed due to the significant synergistic effects by coupling adsorption and photocatalytic reaction of TCNSP composite. As the initial concentration of HA increased, the degradation rate (Kapp) decreased due to HA sorption saturation to the surface of TCNSP composite and the photon interception by HA molecules in aqueous solution. Since the increased loading amount of TCNSP composite enhanced the number of active sites,Kappvalues increased until the optimum loading amount of TCNSP composite. As pH values increased, HA removal efficiency decreased due to increasing electrostatic repulsion between HA and TCNSP composite. Based on the response surface methodology, higher HA removal efficiencies were obtained with acidic condition, longer reaction time, and appropriated loading amount of TCNSP. Further pilot-scale study is in progress using TCNSP composite combined with UVC to remove HA from large amounts of surface water (i.e., 200 m3/d).

Shape Memory Performance of Thermoplastic Amphiphilic Triblock Copolymer poly(D,L-lactic acid-co-ethylene glycol-co-D,L-lactic acid) (PELA)/Hydroxyapatite Composites.

Biodegradable polymer/hydroxyapatite (HA) composites are desired for skeletal tissue engineering. When engineered with thermal-responsive shape memory properties, they may be delivered in a minimally invasive temporary shape and subsequently triggered to conform to a tissue defect. Here we report the shape memory properties of thermoplastic amphiphilic poly(D,L-lactic acid-co-ethylene glycol-co-D,L-lactic acid) (PELA, 120 kDa) and HA-PELA composites. These materials can be cold-deformed and stably fixed into temporary shapes at room temperature and undergo rapid shape recovery (< 3 s) at 50 °C. Stable fixation (>99% fixing ratio) of large deformations is achieved at -20 °C. While the shape recovery from tensile deformations slows with higher HA contents, all composites (up to 20 wt% HA) achieve high shape recovery (>90%) upon 10-min equilibration at 50 °C. The permanent shapes of HA-PELA can be reprogramed at 50 °C, and macroporous shape memory scaffolds can be fabricated by rapid prototyping.

Neurocognitive processing of emotion facial expressions in individuals with self-reported depressive symptoms: The role of personality and anxiety

Neurocognition may constitute one of the numerous factors that mediate the reciprocal influences between personality and depression. The present study explored the influence of personality and anxiety traits on the neurocognitive processing of emotional faces and specifically focused on personal characteristics related to negative (harm avoidance-HA) and positive affectivity (self-directedness-SD) and to anxiety. Twenty participants with self-reported depressive symptoms and 18 control participants were selected based on their BDI-II scores. Personality (TCI-R), anxiety and attention were measured and event-related potentials (ERPs) were recorded during an implicit emotional face perception task (fear, sadness, happiness, neutrality). The participants who self-reported depressive symptoms had higher HA, lower SD and higher anxiety compared to controls. Controls showed enhanced P300 and LPP amplitudes for fear. Individuals with self-reported depression showed reduced ERPs amplitudes for happiness. HA did not account for the difference between the groups but high HA and high anxiety were positively correlated with enhanced P300 amplitude for fear in participants with depressive symptoms. In contrast, SD accounted for the difference between the groups but was not correlated to the ERP components' amplitudes recorded for facial expressions. Other personality dimensions (reward dependence, cooperativeness) influenced the ERPs recorded for facial emotions. Personality dimensions influence the neurocognitive processing of emotional faces in individuals with self-reported depressive symptoms, which may constitute a cognitive vulnerability to depression.

In vitrobiocompatibility analysis of novel nano‐biphasic calcium phosphate scaffolds in different composition ratios

This study aimed to evaluate in vitro biocompatibility of a composite of nanoscale biphasic calcium phosphate (BCP) and collagen (C) compared to pure BCP (P) in different composition ratios of nanohydroxyapatite to nano-β-tricalcium phosphate (HA/β-TCP). Each study group comprised of three ratios of BCP (30/70, 40/60, and 50/50). For evaluation of cellular response toward each ratio, mouse osteoblast (MC3T3-E1) cell line was cultivated on the scaffolds for 19 days. Analysis of cell proliferation, cell viability, cell attachment and morphology, alkaline phosphatase (ALP) activity, and osteocalcin synthesis were done on culture days 1, 3, 7, 13, 15, and 19, appropriately. The scanning electron microscopy showed that the osteoblasts attached successfully to scaffolds surfaces in both BCP groups and in all different ratios by spreading their filopodia and expressing similar viability that was confirmed by confocal laser scanning electron microscope. BCP scaffold (P3070) showed remarkable ALP activity, whereas BCP (P5050) showed highest osteocalcin activity. Collagen coating supported high cell proliferation on culture day 1 and possessed limited benefit restricted to early phase of cell differentiation. In conclusion, the fabricated nanoscale BCP scaffolds offered high biocompatibility and supported well the cell proliferation and differentiation regardless the composition ratio. Furthermore, higher ratio of TCP supported the early phase of cell proliferation, whereas higher HA ratio influenced the later phase. Finally, BCP scaffolds P5050 and C4060 were suggested as candidates for clinical applications.

Temperament and character profiles of Japanese university students with depressive episodes and ideas of suicide or self-harm: A PHQ-9 screening study

ObjectiveThe aim of our study was to reveal the personality traits of individuals with major and other depressive episodes among the young adult population. Furthermore, character traits of individuals with ideas of suicide or self-harm were also investigated in this study. MethodsThe subjects of this study were 1421 university students who completed the Patient Health Questionnaire (PHQ-9) and the Temperament and Character Inventory (TCI). The subjects were divided into three separate groups: the major depressive episode group (N=41), the other depressive episode group (N=97), and the non-depressive controls (N=1283). This separation was achieved using the PHQ-9 algorithm diagnosis. We compared the TCI scores using an analysis of variance. Moreover, the Cochran-Armitage trend test was used to determine the diagnosis, ideas of suicide or self-harm, and analysis of character profiles. ResultsThe major depressive episode group had significantly higher HA (P<0.001), lower RD (P<0.001), lower SD (P<0.001), and lower C (P<0.001) scores than non-depressive controls. The other depressive episode group had significantly higher HA scores (P<0.001) and lower SD scores (P<0.001) than non-depressive controls. The Cochran-Armitage trend test revealed that the prevalence of depressive episodes decreased as the character profiles matured (χ2trend=57.2, P<0.0001). The same tendency was observed in individuals who had ideas of suicide or self-harm (χ2trend=49.3, P<0.0001). ConclusionHigh HA and low SD scores were common personality traits among young adults with major depressive episodes. Furthermore, the immaturity of character profiles was clearly associated with depressive episodes and ideas of suicide or self-harm.

Antagonistic Effects of Humic Acid and Iron Oxyhydroxide Grain-Coating on Biochar Nanoparticle Transport in Saturated Sand

Biochar land application may result in multiple agronomic and environmental benefits (e.g., carbon sequestration, improving soil quality, and immobilizing environmental contaminants). However, our understanding of biochar particle transport is largely unknown in natural environments with significant heterogeneity in solid (e.g., patches of iron oxyhydroxide coating) and solution chemistry (e.g., the presence of natural organic matter), which represents a critical knowledge gap in assessing the environmental impact of biochar land application. Transport and retention kinetics of nanoparticles (NPs) from wheat straw biochars produced at two pyrolysis temperatures (i.e., 350 and 550 °C) were investigated in water-saturated sand columns at environmentally relevant concentrations of dissolved humic acid (HA, 0, 1, 5, and 10 mg L(-1)) and fractional surface coverage of iron oxyhydroxide coatings on sand grains (ω, 0.16, 0.28, and 0.40). Transport of biochar NPs increased with increasing HA concentration, largely because of enhanced repulsive interaction energy between biochar NPs and sand grains. Conversely, transport of biochar NPs decreased significantly with increasing ω due to enhanced electrostatic attraction between negatively charged biochar NPs and positively charged iron oxyhydroxides. At a given ω of 0.28, biochar NPs were less retained with increasing HA concentration due to increased electrosteric repulsion between biochar NPs and sand grains. Experimental breakthrough curves and retention profiles were well described using a two-site kinetic retention model that accounted for Langmuirian blocking or random sequential adsorption at one site. Consistent with the blocking effect, the often observed flat retention profiles stemmed from decreased retention rate and/or maximum retention capacity at a higher HA concentration or smaller ω. The antagonistic effects of HA and iron oxyhydroxide grain-coating imparted on the mobility of biochar NPs suggest that biochar colloid transport potential will be dependent on competitive influences exerted by a number of environmental factors (e.g., natural organic matter and metal oxides).

Mechanical properties of TiO2-hydroxyapatite nanostructured coatings on Ti-6Al-4V substrates by APS method

TiO2-hydroxyapatite (HA) nanostructured coatings were produced by atmospheric plasma spray method. The effects of starting powder composition and grain size on their mechanical properties were investigated. The microstructure and morphology were characterized by X-ray diffraction and scanning electron microscopy (SEM). It is found that the coating with 10% HA has the best mechanical properties. Based on Rietveld refinement method, the mean grain size of the as-received powder (212 nm) extensively decreases to 66.4 nm after 20 h of high-energy ball milling. In spite of grain growth, the deposited coatings maintain their nanostructures with the mean grain size of 112 nm. SEM images show that there is a lower porosity in the coating with a higher HA content. Optical microscopy images show that uniform thickness is obtained for all the coatings.

Interaction of cell culture with composition effects on the mechanical properties of polycaprolactone-hydroxyapatite scaffolds fabricated via selective laser sintering (SLS)

In the current study PCL/HA composites were fabricated using SLS as two- and three-dimensional lattice structures and exposed to a cellular component (MC 3T3 osteoblast-like cells). The main aims were to determine the mechanical differences due to powder composition and to observe the physical and mechanical changes pertaining to cell presence. These structures were characterized by compressive mechanical testing, and the effects of cell culturing and degradation on mechanical properties of the scaffolds with different PCL/HA compositions were determined. Moreover, changes in the scaffold morphology due to the cell culture conditions were determined by μ-CT analysis.Cells steadily grew on the scaffolds for 21days with preferential distribution around the macropores and initially PCL/HA(15%) composites had higher cell numbers. Removal of loosely sintered parts was observable during the culturing period. Cell culture conditions did not change the compressive moduli significantly but had a distinct effect on compressive strength. For PCL/HA(15%) composites, an initial loss in strength caused by cell culture was reversed by longer cell exposure, with compressive strength of the structures restored to the initial properties (p≤0.05). μ-CT measurements showed widespread morphological changes in the scaffolds, such as a decrease in the roughness of the struts. In general, in the initial period composites with lower HA content (15wt.%) showed better metabolic activity compared to the higher HA content, however by day 14 the performance of the two compositions was equal. These results suggest that changes in sintering due to the differences in powder composition can have profound effects on the short and long term mechanical properties of the scaffold particularly under cell culture conditions, and this should be closely considered for SLS processing of scaffolds.

The Fabricated Collagen-Based Nano-Hydroxyapatite/β-Tricalcium Phosphate Scaffolds

The biphasic calcium phosphate (BCP) concept was introduced to overcome disadvantages of single phase biomaterials. In this study, we prepared BCP from nanoHA and β-TCP that were synthesized via a solid state reaction. Three different ratios of pure BCP and collagen-based BCP scaffolds (%HA/%β-TCP; 30/70, 40/60 and 50/50) were produced using a polymeric sponge method. Physical and mechanical properties of all materials and scaffolds were investigated. XRD pattern proved the purity of each HA, β-TCP and BCP. SEM showed overall distribution of macropores (80-200 µm) with appropriate interconnected porosities. Total porosity of pure BCP (93% ± 2) was found to be higher than collagen-based BCP (85%± 3). It was observed that dimensional shrinkage of larger scaffold (39% ± 4) is lower than smaller one (42% ± 5) and scaffolds with higher HA (50%) ratio experienced greater shrinkage than those with higher β-TCP (70%) ratio (45% ±3 and 36% ±1 respectively). Mechanical properties of both groups tend to be very low and collagen coating had no influence on mechanical behavior. Further studies may improve the physical properties of these composite BCP.

Characterization of Modified Fischer–Tropsch Catalysts Promoted with Alkaline Metals for Higher Alcohol Synthesis

Two series of Cu/Co/Cr modified Fischer–Tropsch catalyst promoted with Zn or Mn and an alkaline metal (Me: Li, Na, K, Rb, Cs) were prepared by co-precipitation method and tested for high alcohol synthesis (HAS) at one hour on-stream and at two temperatures, 300 and 350 °C. The results indicate that the best selectivity toward high alcohols depends on temperature and catalysts composition and is obtained as follows: a) at 300 °C over catalysts without Zn and containing K, Na and Rb; b) at 350 °C over catalysts without Zn and containing K; c) at 350 °C over catalysts containing Zn as well as Li and Cs. Two series of Cu/Co/Cr modified Fischer–Tropsch catalyst promoted with Zn or Mn and an alkaline metal (Me: Li, Na, K, Rb, Cs) were prepared by co-precipitation method and tested for HAS at one hour on-stream and at two temperatures, 300 and 350 °C. The results indicate that the higher HA production (i.e. normal and branched butanol) is obtained at 350 °C over catalysts promoted with Zn and all alkali metals, except for Li which shown its best performance at 300 °C.

Physicochemical Characterization andIn VivoEvaluation of Amorphous and Partially Crystalline Calcium Phosphate Coatings Fabricated on Ti-6Al-4V Implants by the Plasma Spray Method

Objective. To characterize the topographic and chemical properties of 2 bioceramic coated plateau root form implant surfaces and evaluate their histomorphometric differences at 6 and 12 weeks in vivo. Methods. Plasma sprayed hydroxyapatite (PSHA) and amorphous calcium phosphate (ACP) surfaces were characterized by scanning electron microscopy (SEM), interferometry (IFM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). Implants were placed in the radius epiphysis, and the right limb of dogs provided implants that remained for 6 weeks, and the left limb provided implants that remained 12 weeks in vivo. Thin sections were prepared for bone-to-implant contact (BIC) and bone-area-fraction occupancy (BAFO) measurements (evaluated by Friedman analysis P < 0.05). Results. Significantly, higher Sa (P < 0.03) and Sq (P < 0.02) were observed for ACP relative to PSHA. Chemical analysis revealed significantly higher HA, calcium phosphate, and calcium pyrophosphate for the PSHA surface. BIC and BAFO measurements showed no differences between surfaces. Lamellar bone formation in close contact with implant surfaces and within the healing chambers was observed for both groups. Conclusion. Given topographical and chemical differences between PSHA and ACP surfaces, bone morphology and histomorphometric evaluated parameters showed that both surfaces were osseoconductive in plateau root form implants.

A Multifunctional 3D Co-Culture System for Studies of Mammary Tissue Morphogenesis and Stem Cell Biology

Studies on the stem cell niche and the efficacy of cancer therapeutics require complex multicellular structures and interactions between different cell types and extracellular matrix (ECM) in three dimensional (3D) space. We have engineered a 3D in vitro model of mammary gland that encompasses a defined, porous collagen/hyaluronic acid (HA) scaffold forming a physiologically relevant foundation for epithelial and adipocyte co-culture. Polarized ductal and acinar structures form within this scaffold recapitulating normal tissue morphology in the absence of reconstituted basement membrane (rBM) hydrogel. Furthermore, organoid developmental outcome can be controlled by the ratio of collagen to HA, with a higher HA concentration favouring acinar morphological development. Importantly, this culture system recapitulates the stem cell niche as primary mammary stem cells form complex organoids, emphasising the utility of this approach for developmental and tumorigenic studies using genetically altered animals or human biopsy material, and for screening cancer therapeutics for personalised medicine.

Osteoblast interaction with laser cladded HA and SiO 2-HA coatings on Ti–6Al–4V

In order to improve the bioactivity and biocompatibility of titanium endosseous implants, the morphology and composition of the surfaces were modified. Polished Ti–6Al–4V substrates were coated by a laser cladding process with different precursors: 100 wt.% HA and 25 wt.% SiO 2-HA. X-ray diffraction of the laser processed samples showed the presence of CaTiO 3, Ca 3(PO 4) 2, and Ca 2SiO 4 phases within the coatings. From in vitro studies, it was observed that compared to the unmodified substrate all laser cladded samples presented improved cellular interactions and bioactivity. The samples processed with 25 wt.% SiO 2-HA precursor showed a significantly higher HA precipitation after immersion in simulated body fluid than 100 wt.% HA precursor and titanium substrates. The in vitro biocompatibility of the laser cladded coatings and titanium substrate was investigated by culturing of mouse MC3T3-E1 pre-osteoblast cell line and analyzing the cell viability, cell proliferation, and cell morphology. A significantly higher cell attachment and proliferation rate were observed for both laser cladded 100 wt.% HA and 25 wt.% SiO 2-HA samples. Compared to 100 wt.% HA sample, 25 wt.% SiO 2-HA samples presented a slightly improved cellular interaction due to the addition of SiO 2. The staining of the actin filaments showed that the laser cladded samples induced a normal cytoskeleton and well-developed focal adhesion contacts. Scanning electron microscopic image of the cell cultured samples revealed better cell attachment and spreading for 25 wt.% SiO 2-HA and 100 wt.% HA coatings than titanium substrate. These results suggest that the laser cladding process improves the bioactivity and biocompatibility of titanium. The observed biological improvements are mainly due to the coating induced changes in surface chemistry and surface morphology.

Increase in harm avoidance by genetic loading of schizophrenia

BackgroundSchizophrenia is highly familial neuropsychiatric disorder with heritability estimated at 60% to 90%. Even unaffected first-degree relatives of schizophrenia manifested some neuropsychologic abnormalities, neurologic soft sign, and morphologic anomalies. Because personality traits are under genetic influence and considerable heritability, we intended to evaluate temperament and character of first-degree relatives of schizophrenia and the influence of schizophrenia genetic loading on their temperament and character. MethodsTemperament and Character Inventory was completed by 97 first-degree relatives of schizophrenia or schizoaffective disorder, 48 schizophrenic probands (44 patients with schizophrenia and 4 patients with schizoaffective disorder), and 106 control subjects. Within first-degree relatives, parents who have additional probands with schizophrenia spectrum disorder in their ascendant or collateral pedigree and siblings who have offspring with schizophrenia spectrum disorder were defined as presumed carriers (n = 20). Group differences in Temperament and Character Inventory scores were compared using a mixed-model analysis of variance with family as a random effect and age as a covariate. ResultsHarm avoidance (HA) scores increased in the order of control subjects, the first-degree relatives, and probands. Among the relatives, presumed carriers, but not presumed noncarriers, had higher HA compared with control subjects. In addition, probands showed significantly low reward dependence, low self-directedness, and low cooperativeness scores compared with the first-degree relatives and control subjects. Probands had also higher self-transcendence scores than the first-degree relatives and had lower persistence scores than control subjects. ConclusionsOur findings that HA increases in proportion to the genetic loading of schizophrenia suggest that it may be a potential endophenotype of schizophrenia.